1. Field of the Invention
This invention pertains to locking apparatus, and more particularly to apparatus for locking a mobile storage unit in a predetermined location.
2. Description of the Prior Art
It is well known to equip mobile filing and storage systems with locking mechanisms. For example, my co-pending U.S. patent application Ser. No. 514,114, filed July 15, 1983, discloses a locking mechanism used in conjunction with a handwheel which aids the movement of the storage unit along floor tracks. Although the locking mechanism disclosed in patent application Ser. No. 514,114 provides excellent operating qualities, it is limited to use with a handwheel operated system. It is thus not satisfactory for electrically driven storage units or for manually moved units that are not handwheel operated.
Another drawback of previous locking devices is that they must be set in the locked mode only when the storage unit is at the desired location along the tracks. Damage usually results if the lock is actuated and then the storage unit is moved. Further, prior locking mechanisms are designed such that they firmly lock the storage units against movement in two directions. It is not possible, for example, for a locked storage unit to be freely movable in one direction but to be prevented from moving in the opposite direction. The necessity of always unlocking the storage unit before moving it and then relocking it at the new location is inconvenient and undesirable, particularly if only small increments of motion are required.
Thus, a need exists for a mobile storage system locking apparatus which may be actuated to the locked mode prior to moving the storage unit to the desired locked location and which firmly locks the storage unit in place against unintended motion.